163 research outputs found

    Performance and design of consensus on matrix-weighted and time scaled graphs

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    In this paper, we consider the H2\mathcal{H}_2-norm of networked systems with multi-time scale consensus dynamics and vector-valued agent states. This allows us to explore how measurement and process noise affect consensus on matrix-weighted graphs by examining edge-state consensus. In particular, we highlight an interesting case where the influences of the weighting and scaling on the H2\mathcal{H}_2 norm can be separated in the design problem. We then consider optimization algorithms for updating the time scale parameters and matrix weights in order to minimize network response to injected noise. Finally, we present an application to formation control for multi-vehicle systems.Comment: 10 pages, 5 figures, accepted to the IEEE Transactions on Control of Network Systems. arXiv admin note: text overlap with arXiv:1909.0786

    DIFFERENT OPTIMIZATION TECHNIQUES OF WIRELESS MESH NETWORKS FOR PHOTOVOLTAIC APPLICATION

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    With the advancement of technology the internet technology is evolving and it is facing new challenges to the betterment of the quality of service. Mesh Networks are an important topology where the fixed wireless network is established to provide network services. Wireless Mesh Network (WMN) is getting acknowledgment for advanced networking purposes. Mainly performance of this kind of network is dependent on the assignment of the channel and the scheme of routing. The photovoltaic network is a new concept that is combined with the Internet of Things to take advantage of the panel’s monitoring system. Large-scale WMN, combined with a photovoltaic system requires optimization techniques to improve the quality and efficiency of service. Covering and sharing information between all nodes in the network is crucial for PV and the Internet of Things (IoT). Power consumption is a significant part of low-power WMN and IoT. This article provides different optimization techniques and analyzes different algorithms to understand the better solution for a wireless mesh network in the ground of photovoltaic networking

    Controlling complex networks: How much energy is needed?

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    The outstanding problem of controlling complex networks is relevant to many areas of science and engineering, and has the potential to generate technological breakthroughs as well. We address the physically important issue of the energy required for achieving control by deriving and validating scaling laws for the lower and upper energy bounds. These bounds represent a reasonable estimate of the energy cost associated with control, and provide a step forward from the current research on controllability toward ultimate control of complex networked dynamical systems.Comment: 4 pages paper + 5 pages supplement. accepted for publication in Physical Review Letters; http://link.aps.org/doi/10.1103/PhysRevLett.108.21870

    The philosophical analysis of technology and its relation to cyberspace

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    Background and Objective:Technology is a widespread and vital event in the present time. The digital form and the telecommunications sector, which have been accompanied by the transformation of social structures, have transformed the daily life more than the biological arenas and the ecology. The essence of technology is not neutral to be passive in the face of human affairs such as culture, but between technology and the production of thought has always been a two-way relationship. Technology has its own knowledge and is related to the philosophical infrastructure of time and it changes with them. This type of knowledge is based on performance and does not have a metaphysical nature. One of the technological events is the realization of a cybernetic space that is closest to the nature of technology. This proportion is due to the technological nature of cyberspace, the new human habitat in the form of transhumanism and the desire to circulate information rhizome, multidimensional and decentralized. The purpose of this research is the philosophical analysis of technology and to find its relation with cyberspace that is done analytically. Methods: The type of research is applied and the research method is analytical-documentary. Findings: Research findings show that what brings an object to the technological level is its structure and rationality, which both meet biological needs and generate new needs for humans; and progresses in a dialectical process to find its relation to the production of thought. Also, the study of the relationship between thought and technology shows that the Gestalt attitude towards technology is related to the relationship between man and technology. This ratio is explained by the specific knowledge of technology based on its conceptual basis in postmodern knowledge. The knowledge that is flexible, relative, and fragile and does not fit into the rational methods of modernism is present in cyberspace, which is the most pervasive form of technological events and, above all, reflects the nature of technology, in the form of pretense, two-tier, and network development. In the section related to human relationship with technology, it was discussed that human beings as creators and users of technology, when faced with a non-technological position, face challenges in the field of ethics, meaning-seeking, transcendence, type and extent. They face responsibility and understand the true relationship with their body and use all their material and spiritual resources to respond to them. Finally, in an ideological context that depicts man's confrontation with technology, cyberspace emerges as an expressive and broad form of technology; an atmosphere that clearly reflects the nature of technology and is a platform for the intersection of technology and society. Research findings show that the abundant entanglement of humans with technology indicates the dominance of the technical object. This dominance is so great that it serves the idea of ​​absolute interconnectedness of the world to more accurately describe the functional life of postmodern man, who has cybernetic imaginary structures and suffers from narcissistic hallucinations as a result of technicality, cyber-extremes and detachment from physical incarnation. Conclusion: The results indicate that the dominance of the technological object and its effects in cyberspace has led to a decrease in responsibility, conflict with the category of meaning, transcendence and moral encounters.   ===================================================================================== COPYRIGHTS  ©2019 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

    Novel links between ciliopathies and FGF-related craniofacial syndromes

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    K Liu1*, JT Tabler1, HL Szabo-Rogers1, A Mesbahi1, C Healy1, W Barrell1, B Wlodarczyk2, Author Affiliations 1 King's College London, UK 2 University of Texas Southwestern, USA 3 University of Texas at Austin, USAOral Presentation : Recent studies suggest that planar cell polarity (PCP) genes coordinate cell polarity, ciliogenesis and signalling during mammalian development. FUZ is a PCP gene implicated in human congenital anomalies, including neural tube defects and orofacial clefting. Our analysis of fuzzy mutant mice reveals ciliogenesis defects in craniofacial tissues as well as a suite of phenotypes reminiscent of FGF-related craniofacial disorders. Mutants have coronal synostosis, shortened facial extensions, low-set ears and a high-arched palate. To our surprise, we found that the facial defects are due to increased neural crest migration into the first branchial arch (BA1), resulting in maxillary hyperplasia. Furthermore, the neural crest cells migrate in a disorganized fashion, deeper than normal and with fewer cell-cell contacts. This ectopic migration correlates with a dramatic increase in FGF signaling, first in the mid-hindbrain boundary, and then in the BA1 epithelia. The increased tissue causes a medial positional shift in the palatal primordia that manifests as a high-arched palate with pseudo-cleft. Genetic loss of fgf8 rescues the maxillary hyperplasia. Taken together, our data suggest a novel interplay between ciliogenesis, FGF signalling and migration of neural crest which may underlie congenital craniofacial dysmorphologies.Molecular [email protected]

    Tropheryma whipplei tricuspid endocarditis: a case report and review of the literature

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    INTRODUCTION: The main clinical manifestations of Whipple's disease are weight loss, arthropathy, diarrhea and abdominal pain. Cardiac involvement is frequently described. However, endocarditis is rare and is not usually the initial presentation of the disease. To the best of our knowledge, this is the first reported case of a patient with Tropheryma whipplei tricuspid endocarditis without any other valve involved and not presenting signs of arthralgia and abdominal involvement. CASE PRESENTATION: We report a case of a 50-year-old Caucasian man with tricuspid endocarditis caused by Tropheryma whipplei, showing signs of severe shock and an absence of other more classic clinical signs of Whipple's disease, such as arthralgia, abdominal pain and diarrhea. Tropheryma whipplei was documented by polymerase chain reaction of the blood and pleural fluid. The infection was treated with a combined treatment of doxycycline, hydroxychloroquine and sulfamethoxazole-trimethoprim for one year. CONCLUSION: Tropheryma whipplei infectious endocarditis should always be considered when facing a blood-culture negative endocarditis particularly in right-sided valves. Although not standardized yet, treatment of Tropheryma whipplei endocarditis should probably include a bactericidal antibiotic (such as doxycycline) and should be given over a prolonged period of time (a minimum of one year)

    Clinicopathological, therapeutic and prognostic features of the triple-negative tumors in moroccan breast cancer patients (experience of Hassan II university hospital in Fez)

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    <p>Abstract</p> <p>Introduction</p> <p>Triple-negative breast cancer (TNBC) is defined as a group of breast carcinomas that are negative for expression of hormone receptors (ER, PR) and Her2, we can distinguish between two groups: basal-like (ER-, PR-, Her2-, cytokeratin (CK) 5/6+ and/or Her1+) and unclassified subtype (ER-, PR-, Her2-, Her1- and CK5/6-).</p> <p>The aim of this study is to determine the clinicopathological, histological, therapeutic and prognostic features associated with this type of breast cancer.</p> <p>Methods</p> <p>This is a retrospective study of 366 female breast cancer patients, diagnosed between January 2007 and June 2010 at the Department of Pathology. Epidemiological, clinical, histological, therapeutic and evolutive data were analyzed. OS and DFS rates were estimated by Kaplan-Meier analysis and a log-rank test to estimate outcome.</p> <p>Results</p> <p>A total of 64 women were identified as having TNBC (17.5% of all female breast cancer patients), 12.6% were basal-like, 4.9% were unclassified subtype, with a median age of 45 years. The median histological tumor diameter was 4.3 cm. TNBC were most often associated with a high grade, 49.2% grade III (53% for unclassified subtype, 47.6% for basal-like). Vascular invasion was found in 26.6% of cases (22% for unclassified subtype and 28.3% for basal-like). For the lymph node involvement: 51% had positive lymph nodes, and 22.4% had distant metastases. Neoadjuvant chemotherapy was administered to 18% patients with 26% of complete pathologic response; therefore adjuvant chemotherapy was given to 82%. 98% received anthracycline based regimen and only 30% received taxanes.</p> <p>The Kaplan-Meier curves based showed the lowest survival probability at 3-years (49% of OS, and 39% of DFS).</p> <p>Conclusion</p> <p>TNBC is associated with young age, high grade tumors, advanced stage at diagnosis, difference chemo response compared to other subtypes, and shortest survival. Critical to optimal future management is accurate identification of truly triple negative disease, and adequately powered prospective TNBC trials to establish treatment efficacy and define predictive biomarkers.</p
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